This relates ladder safety devices. More particularly, it relates to a means for stabilizing a ladder supported by an aerial cable.
A common tool of a utility repairman and installer is the ordinary ladder. However, it has been found that ladders are a common source of injury because of their inherent instability. Various devices have been used to stabilize ladders which are used for climbing utility poles. One such device is described in U.S. patent application Ser. No. 423,175 filed Oct. 16, 1989 titled Pole Gripping Ladder Stabilizing Device invented by Kenneth H. Henson who is also the inventor in the present application. The Henson prior patent application describes a stabilizing device which is designed to be clamped to the telephone pole itself. However, in many cases a repair or installation must take place between utility poles.
In some cases utility installers and repairmen simply lean the ladder against the telephone wire. Obviously this method is fraught with risk to the user. Attachments to ladders so that a ladder may be used at mid-span between utility poles have been described. Examples include U.S. Pat. No. 2,963,104 issued to Roth and U.S. Pat. No. 3,001,603 issued to Krause, both titled Conductor Spreaders and Ladder Hangers. The Roth and Krause patents show attachments at the far end of a ladder which include a plurality of slots which receive electrical conductors.
In a somewhat related area, U.S. Pat. No. 3,780,829 assigned to Valley Engineering, Inc. teaches the use of an attachment to a ladder for evacuating persons from chair aerial cable lifts. The Valley Engineering patent shows a hook mechanism which is clamped over the aerial cable near a chair having a person to be evacuated.
Other related patents include U.S. Pat. No. 1,994,369 issued to Risser and U.S. Pat. No. 1,961,289 issued to Garnder, both of which teach the use of attachments for ladders which contact a utility pole. However, it is believed that none of these above-described patents provide a commercially acceptable mechanism to safety use a ladder at mid-span between utility poles.